Condensed Matter > Strongly Correlated Electrons

Title:
Emergent supersymmetry at the Ising-Berezinskii-Kosterlitz-Thouless multicritical point

Abstract: We show that supersymmetry emerges in a large class of models in 1+1
dimensions with both Z_2 and U(1) symmetry at the multicritical point where the
Ising and Berezinskii-Kosterlitz-Thouless transitions coincide. To arrive at
this result we perform a detailed renormalization group analysis of the
multicritical theory including all perturbations allowed by symmetry. This
analysis reveals an intricate flow with a marginally irrelevant direction that
preserves part of the supersymmetry of the fixed point. The slow flow along
this special line has significant consequences on the physics of the
multicritical point. In particular, we show that the scaling of the U(1) gap
away from the multicritical point is different from the usual
Berezinskii-Kosterlitz-Thouless exponential gap scaling.